Process and apparatus for purifying acid electrolyte used in refining copper.



C. H. ALDRIGH & J. K. BRYAN'. PROCESS AND APPARATUS 1:"0R PURIPYING ACID ELEGTROLYTE USED IN REFINING COPPER.

I APPLICATION FILED JUNE 25, 19.10. Y 991,685.

Patented May 9, 1911.

INI/E TORS @MAW/W v, I.. Y l

lll/1111117 UNITED STATES PATENT oEEIoE.

CHARLES H. ALDRICH AND JOHN K. BRYAN, OF PERTH AMBOY, NEW JERSEY.

PROCESS AND APPARATUS FOR PURIFYING ACID ELECTROLYTE COPPER.

USED IN RErrNrNG Patented May 9, 1911.

Application filed .Tune 25, 1910. Serial No. 568,783.

To all whom it may concern:

Be it known that We, CHARLES H. AL-V DRICH and JOHN K. BRYAN, citizens of the United States, and residents of Perth Amboy, county of Middlesex, State of New Jersey, have invented certain new and useful Improvements in Processes and Apparat-us for PurifyingAcid Electrolyte Used in Refining Copper, of which the following is a specification.

The present invention relates to the purification of the acid electrolyte used in the electro-lytic refining of copper and has for its main purposes, first, the provision of a process whereby the impurities will be fractionally separated out from the electrolyte, second, the provision of a process whereby arsenic and antimony may be electrolytica-lly separated rfrom mother liquor from which the iron, copper, zinc etc. have been substantially removed, and third, the provision of an apparatus for carrying, such process into eect in a rmost practicable manner.

In the electrolytic refining of copper the solution becomes impure and it is necessary to remove large quantities of the same periodicallyv in order to maintain the. requisite purity ofthe electrolyte. j

he common practiceis to crystallize out the bulk of the copper as blue vitriol, sometimes with the previous step of neutralizing the free acid of the electrolyte by passing over shot copper, and sometimes without .suchstep of neutralization, and then precipitate the remaining iron. In either case, the residue is discarded; though it has been proposed to subject this residue to further purification steps With a.- view of separating by precipitation the acid salts, as iron, arsenic, and antimony therefrom. In these proposals, the copper, iron and nickel are not fractionally separated out of the mother liquor, nor arek the arsenic and antimony separated from the residue.

Inthe accompanying drawings there is illustrated an apparatus edesigned to carry copper on scrap into effect the novel process of the present invention, saidapparatus being shown partly in section and partly diagrammatically.

In the practice of the present process, the impure electrolyte, ,which is of about 18 to 25, Baume, is concentrated to about 45 Baume, in a lead lined tank A, by heatingv by means of lead coils, or otherwise as de# sired. This is delivered in any suitable manner to an iron pan B, preferably lead lined, and is therein concentrated to about 50 Baume. At this density the settling of the.anhydrous salts to the bottom of the pan commences. The salts are allowed to crystallize out until the bulk of the copper is removed. Thus far the process is the one usually pursued. In accordance with the present process, however, instead of precipitating the copper, nickel and iron salts in one pan, the mother liquor,after the bulk of the copper has beenseparated out, isA subjected successively to steps of precipitation adapted fractionally to separate the nickel, copper and iron salts therefrom, and

thereby secure a better separation thereof. l

, C and D, whose number depends on the percentage of nickel, copper and iron salts in.

the mother liquor. The pans are arranged in cascade and they are artificially heated byv products of combustion which flow beneath the series of pans, B, C and D through a heating passage E extending from a furnace F contiguous to the last pan (as D) ofthe series to a stack G adjacent to the first pan (as B) of the'series. The communica-tion between these pans is preferably provided bymeans of doverflow pipes b and c respectively. The pans vC and D may be lead lined. By this described method the mother liquor is concentrated to labout 60 or 7 0, Baume, the salts beingv fractionally precipitated in the cascade of pans, the precipitate inthe first pan or pans being rela'- tively rich in copper, that in the intermediate pan or pans containing copper and nickel in approximately equal quantities, and that in the last pan -or pans being relatively rich in nickel.

The anhydrous salts are handled in any suitable manner for purification.

The result-ing solution is allowed to settle in a leadlined tank', H, having communication With the tank D preferably by means of an overflow pipe d leading from the latter and from the tank H is pumped, by means of a pump M, into an electrolytic refining tank or into electrolytic refining tanks, I, J', K, L preferably arranged in cascade and haying communication with each other by metal that does not dissolve in the electrolyte employed ,formingL the cathodes. The

electrolysis is continued until the bulk of the arsenic ytogether with traces of the copf a deposit on the cathodes.

arsenic is left in solution tol prevent the per and antimony have been precipitatedas- Only enough:

formation of arsine on the cathode. If suitabley Ventilating systems are employed pracf tically all the arsenic can be removed from the'solution. Our experience has shovvn that lso the presence of a trace of copperf, as copper.7 sulfate, in the arsenic lelectrolyte is advan t-ageous, as it facilitates the deposition o fj-,the arsenic.

per, antlmony etc. from which it can be.

easily separated and recovered. by burning in a small furnacel provided? with suitable condensing fiues. The`residue .is composed principally of copper oXid which is `Worked up in a blast furnace inthe lusual Wayf. rI "he f liquor which has beenthus purified'ifiows from the last electrolytic tank, L, the series through anl overflow pipel intoja 'tank N, Where itis permitted to settle and? from which it may be returned to the copperfreining bath. I i rj'gfif' It is to be understood that numerous changes can-be made in the details lof. the process and apparatus hereiiibe'fore vdescribed vvithout departing from the spirit of 'the invent-ion or the scope ofthe appended claims. i

Having novv described our invention what we believe to be new and desire to secure by Letters Patent, is:

1. The herein described process of purifyino' the electrolyte produced in theelectrolytic refining of copper which consists in re-v moving the greater portion of thecontained copper, concentrating the residue until all but traces of the copper, nickel, iron and zinc contained are precipitated and separating the arsenic and antimony with traces of ot er impurities from the resulting solution by electrolysis.'

2. The herein described process of purify ing the electrolyte produced in the electrolytic refining of copper which consists in removing the greater portion of the contained copper, Qoncentrat-ing the residue by successive stages until allx but traces of the copper, nickel, iron and zinc contained therein are precipitated, and freeing the arsenic and The arsenic deposit containsf cop-Y ing the electrolyte antimony With traces of other impurities by electrolysis-.` L

3. The hereipdescribed process of purifying the electrolyte produced in the electro lytic refining ofcopper which consists in removing the greater portionnof the contained copper, concentrating the residue by succes sive stages until all but traces kof lthe copper, nickel, iron and zinc contained therein are precipitated and freeing the arsenic and antimony with traces of other impurities by electrolysis at a temperature of approXimately 170o to v180" 4. The herein described-process of purifying the electrolyte produced in the electrolyti-c refining of copperwhich consists in re moving the greater portion of the contained 7copper by concentration and crystallization,

concentrating the residue by successive stages to about 709 Baum,.separating the electrolytefrom the precipitate and finally separating t-he remaining metallic impurities from the ele'ctrolytefby electrolysis.

The herein described process of purifylytic refining of copper '.vhich consistsin removing the-greater portion of the contained copper by concentration, .removing the mother liquor from the precipitate, concentrating the mother liquor by successive stages, separating the mother liquor; from the precipitate formed from the last concentration, and finally removing the remaining metallic impurities by electrolysis.

6. The herein described process of purifying the electrolyte producedin thelelecfrolyticV refining of copper Which consists -in removmg the greaterportion of the contained copper by concentration to about 50o Baume and removal of the mother liquor from the precipitate, concentrating the mother liquor by successive stages to about 70D-72 Baume,

'separating the mother liquor from the precipitate formed and finally removing the remaining metallic impurities by electrolysis at approximately 170L-180? 7 The herein described process of purifying the electrolyte produced in the electrolytic refining ofcopper Which consists in removing the greater @portion of othe contained copper by concentration and crystallization, concentrating the residue until all but traces of the copper, zinc cont-ainedtherein are precipita-ted, freeing the electrolyte from the precipitate, and finally separating the arsenic and antimony and traces of other metallic impurities'com tained in the residue of the electrolyte by electrolysis.

l. L8. The herein describedprocess of purifying the electrolyte produced in the electrolytic refining of copper which consists 'in removing thegreater portion of the contained copper by concentration and crystallization,

producedloin the electro` nickel, ironand l'senaat .rating the arsenic, antimony and traces ofy the other metal impurities contained in the residue of the electrolyte by electrolysis.

' 9. The herein described .process of purifying the electrolyte produced in the elect-rolytic refining of copper which consists in removing the greater portion of the containedcopi per by concentration, separating the elec-- trolyte from the precipitate formed, concentrating the electrolyte by passing it through a plurality of heated containers arranged in 'cascade wherein the solution is concentrated, and all but traces of the metallic impurities, except arsenic and antimony,l contained therein are precipitated, separating the electrolyte from the precipitate, and finally separating the arsenic, antimony and traces of the other metal impurities contained therein by electrolysis.

10. The herein described process of purifying the electrolyte produced in the electrolytic refining of copper which consists in removing the greater portion of the contained copper by concentration, separating the lelectrolyte from the precipitate formed, concentrating the electrolyte by passing it through a plurality of heated containers arranged in cascade wherein the solution is concentrated and all but traces of the copper, nickel, ironv and zinc contained therein are precipitated, separating the electrolyte from the precipitate, and finally separating the arsenic, antimony and traces of other metal impurities contained therein by electrolysis. l1. The herein described process of purifying the electrolyte produc-ed in the electrolytic refining of copper Which consists in r`emoving the greater portion ofthe contained copper by concentration to about 50 Baume separating the electrolyte from the precipitate formed, concentrating the electrolyte bypassing it through a plurality of heated containers arranged in cascade wherein the solution is concentrated to approximately Y0-72 Baume and all but traces of the copper, nickel, iron and zinc contained therein are precipitated, separating the electrolyte from I, the precipitate and finally separating the ars eis senic, antimony and traces of other metal -impurities contained therein` electrolysis at approximately from 170480lo F. 12. Thel herein described process of purifying the electrolyte produced in the electrolytic rening of copper, the step of fractionally separating out metallic impurities from the electrolyte, which consists in passing the electrolyte through afse'riesof heated containers varranged in cascade.

13. In the herein describedfprocess of pur'rlelectrolyte WhichV has been-"substantially freed from -other metallic impurities, consisting in subjecting the solution to an electrolytic action. l

14. In the herein described process of purifying the electrolyte produced in the electrolytic refining of copper, the step of separating the arsenic and antimony from the electrolyte Which has'been substantially freed from other metallic impurities, consisting in subjecting the solution `to an electrolytic actionsuccessively ina series of containers arranged in cascade.

15. An apparatus for purifying the electro-lyte produced in the electrolytic refining of copper, comprising means for removing the greater portion of the contained copper, means nadapted for concentration of the residue until all but traces of the copper, nickel, ironand zinc are precipitated and means u adapted electrolytically to separate therefrom the arsenic and antimony With traces of other metal impurities contained therein.

16; An apparatus for purifying the electrolyte produced in the electrolytic refining of copper, comprising means for removing the greater portion of the contained copper, and a series of heatedcontainers arranged in cascade wherein the electrolyte is gradually concentrated by evaporation whereby all butC traces of copper, nickel, iron and. zinc con-n tained therein is fractionally separated from the residue.

17. An apparatus for purifying the elecp trolyte produced in the'electrolytic rening of copper, comprising means for removing the greater portion of the contained copper, 105

-a series of heated containers arranged in cascade wherein the electrolyte-is gradually concentrated by evaporation whereby all but traces of copper, nickel, iron and zinc contained therein is fractionally separated from the residue, and means adapted to separate arsenic and antimonypfrom the liquor by electrolysis. C

18. An apparatus for purifying the electrolyte produced in the electrolytic refining of copper, comprising means lfor removing the greater portion ofthe contained copper,- a series of heated containers arranged in cascade for fractionally separating from the residue all but traces of copper, iron and 12o zinc contained therein, and means for separating arsenic and antimony from the liquor by electrolysis, the latter means comprising a 'series of electrolytic containers, having connection with each otherfand With the first mentioned series of containers.

19. The herein described apparatus for purifying the. electrolyte producedv in 'the electrolytic refining of copper, comprising'l a heated concentrating tank, a series of on- 13o nected heated containers arranged in cascade and having connection With said tank, said containersi ractionally removing copper, nickel, ete., from the electrolyte, a settling tank having means -for communication withy said series of containers, a pump connected With the settling tank, and a series of con nected containers having connectionvviththe pump and providedwith means for removing arsenic and antimony from the solution by electrolysis.v

ln Witness whereof Weg/'have hereunto'set ourhands at Perth Amboy, county of Middlesex, and State of Nevl? Jersey,l this 17th 15 day of June, 1910.

CHARLESv H. ALDRICH. JOHN K. BRYAN.

In presence of- A. O. RULEMANN, CEAS. J. WARNER. 

